#1: Research - As you've probably noticed, many scholarships are generous national awards that'll likely be quite competitive. Unfortunately, you could be a strong applicant for many of these scholarships and still not win a big award. So what's a student to do?
The reality is that there are countless scholarship programs out there that might be really good fits for your interests, location, background, identity, etc. The more niche a scholarship program is, the better chances you'll have of winning an award. So do some research on scholarships programs that operate in your area or are offered to students with your particular interests, experiences, skills, or passions.
#2: Deadlines - Scholarship applications are all over the place—there's no defined "scholarship season" for submission deadlines, but many are due before college application deadlines. As such, it's better to start your scholarship search sooner rather than later so you don't miss out on any great opportunities. The summer before your senior year is a good time to start making note of programs you're interested in. Keep track of application deadlines by maintaining a spreadsheet that you update regularly. This is especially helpful if applications require you to ask for letters of recommendation; you can make sure to give teachers and mentors plenty of advance notice to write you a letter.
#3: Apply Broadly - Applying for scholarships—like applying to colleges—is, in part, a numbers game. You wouldn't apply to just one school if you wanted to optimize your chances of getting into a great college, would you? Many scholarship applications ask similar questions and require similar information, so if you apply to one program, you might as well apply to a bunch. It's free to apply —all it takes is a few hours of your time. Finally, take advantage of applications that submit you for consideration for many scholarship awards, such as the Horatio Alger Scholarship.